Akka/Scala example source code file (AveragingGauge.scala)

This example Akka source code file (AveragingGauge.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

akka, averaginggauge, double, gauge, long, longadder, metrics, seq, test, testing, testkit

The AveragingGauge.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.testkit.metrics

import com.codahale.metrics.Gauge

/**
 * Gauge which exposes the Arithmetic Mean of values given to it.
 *
 * Can be used to expose average of a series of values to [[com.codahale.metrics.ScheduledReporter]]s.
 */
class AveragingGauge extends Gauge[Double] {

  private val sum = new LongAdder
  private val count = new LongAdder

  def add(n: Long) {
    count.increment()
    sum add n
  }

  def add(ns: Seq[Long]) {
    // takes a mutable Seq on order to allow use with Array's
    count add ns.length
    sum add ns.sum
  }

  override def getValue: Double = sum.sum().toDouble / count.sum()
}